980MPA GRADE COLD-ROLL STELL SHEETS WITH HIGH HOLE EXPANSION RATE AND HIGHER PERCENTAGE ELONGATION AND MANUFACTURING METHOD THEREFOR

Title:

980MPA GRADE COLD-ROLL STELL SHEETS WITH HIGH HOLE EXPANSION RATE AND HIGHER PERCENTAGE ELONGATION AND MANUFACTURING METHOD THEREFOR

Document Type and Number:

WIPO Patent Application WO/2020/108597

Kind Code:

A1

Abstract:

Disclosed is a 980MPa grade cold-roll steel sheets with high hole expansion rate and higher percentage elongation as well as a manufacturing method therefor. The mass percents of chemical components in the steel sheet are as below: C: 0.08%～0.12%, Si: 0.1%～1.0%, Mn: 1.9%～2.6%, Al: 0.01%～0.05%, Cr: 0.1～0.55%, Mo: 0.1～0.5%, Ti: 0.01～0.1%, the rest being Fe and other inevitable impurities. The steel plate has a yield strength greater than 600MPa, a tensile strength greater than 980MPa, a percentage elongation greater than 11%, a hole expansion rate greater than or equal to 45%, and a tensile strength up to 980MPa grade; the microscopic structure is ferrite plus bainite plus martensite, with the volume fraction content of ferrite greater than 10%, the volume fraction content of bainite greater than 30%, and the volume fraction content of martensite greater than 15%; the microscopic structure further comprises nanoscale precipitates in uniform dispersion distribution, the average size of precipitates being less than 20nm.

Inventors:

XUE PENG (CN)
ZHU XIAODONG (CN)
LI WEI (CN)

Application Number:

PCT/CN2019/121868

Publication Date:

June 04, 2020

Filing Date:

November 29, 2019

Export Citation:

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Assignee:

BAOSHAN IRON & STEEL (CN)

International Classes:

C22C38/02; C21D8/02; C22C33/04; C22C38/04; C22C38/06; C22C38/22; C22C38/28

Foreign References:

CN109576579A	2019-04-05
CN105734410A	2016-07-06
US7371294B2	2008-05-13
CN108193139A	2018-06-22
CN103492599A	2014-01-01
CN105874086A	2016-08-17
US20180023155A1	2018-01-25
KR101858852B1	2018-06-28

Other References: